New Delhi, Feb. 10 -- A 16-year-old boy was stabbed to death by four minors outside a school in north Delhi's Mangolpuri on Monday, police said, adding that the accused - all schoolmates of the victim - had allegedly planned the attack. Police said the victim was on his way to school in the morning when he was confronted by a group of boys who began fighting with him. During the assault, a sharp-edged weapon, suspected to be an ice pick, was used to stab him. The weapon was later found lodged in the boy's skull, officers said. The victim, identified as Chiranshu, was taken to Sanjay Gandhi Memorial (SGM) Hospital, where he was declared dead. Police said four minors were apprehended within hours of the incident. Investigators said that prima facie, one of the accused - also 16 - had a fight with the victim a few days ago over a petty issue and decided to take "revenge". Mangolpuri police station received information about the stabbing at 1.09pm. The caller reported that a Class 10 student had been stabbed near a water tank next to a Delhi government school and he has been shifted to hospital, added police. "It was horrifying. I was dropping my son and was on the opposite side of the road. I saw the boy with a weapon stuck in his skull. He was running and trying to take it out. People were trying to help him but he soon collapsed. The boys were chasing and stabbing him. They fled the scene after we all gathered to help the boy," said a woman who lives nearby. DCP (Outer) Sachin Sharma said the injured boy had already been shifted to hospital by the time police reached the spot. "The body has been shifted to the mortuary for post-mortem. The motive behind the incident is being ascertained," he said, adding that a case has been registered. The boy's father said his son was preparing for his pre-board examinations. "My son was very hardworking. He was going to collect the date sheet. I am shocked something like this would happen near a school. He had no enmity with anyone," he said....